Abstract

The major route of exposure of humans to the toxic element cadmium (Cd) is via the consumption of vegetables homegrown on Cd contaminated soil. It is well known that soil pH is one of the main soil properties controlling bioavailability of Cd in plants. This is acknowledged in human health risk assessment models that incorporate pH dependant concentration factors (CF=plant Cd/soil Cd). However, variation in spatial heterogeneity of nutrients and heavy metals in soil can have a profound effect on plant performance and uptake of nutrients and heavy metals.Here we show for lettuce (variety Crispino) that variation in plant-scale heterogeneity of Cd in soil affects bioavailability and hence CF by a factor of 2.Plant yield is also significantly affected. This has important implications for both human health risk assessment, as variation in CF affects predicted exposure, and for phytoremediation where an optimal combination of plant yield and contaminant accumulation is required.

Item Type:

Article

Additional Information:

Millis was Ramseys graduate student. John collaborated, as ecologist in the same Department. First paper to investigate the implications of the (previously overlooked) heterogeneity of this toxic elements, on the risk to human health via the uptake of Cd from soil into food plants.